Method of constructing heat exchangers



Aug. 16, 1966 F. FROHLlCH 3,266,129

METHOD OF CONSTRUCTING HEAT EXCHANGERS Original Filed Nov. 5, 1961 6 Sheets$heet 1 8 2 2 8 1* v N I w v I M i Aug. 16, 1966 F, FRC'QHLICH 3,266,129

METHOD OF GONSTRUCTING HEAT EXCHANGERS Original Filed Nov. 5, 1961 3 Sheets-Sheet 3 United States Patent 3,266,129 METHOD OF CONSTRUCTING HEAT EXCHANGERS Franklin Friihlich, 39 St. Leonhardstrasse, St. Gallen, Switzerland Original application Nov. 3, 1961, Ser. No. 150,012 now Patent No. 3,207,213, dated Sept. 21, 1965. Divided and this application Aug. 3, 1965, Ser. No. 489,448 1 Claim. (Cl. 29-1573) This application is a divisional application based on the parent United States patent application Serial Number 150,012 filed November 3, 1961, now US. Patent No. 3,207,213, granted September 21, 1965.

This invention relates to a heat exchanger and to a method for constructing the same.

In my Swiss Patent No. 283,884 a heat exchanger unit is disclosed which consists of a plurality of parallel, technical silicate plates that are spaced by spacer strips. Owing to the brittleness and relatively large size of the plates, great care must be exercised to avoid breakage as the elements are stacked, clamped together with suflicient force to effect a proper seal, and mounted in a heat exchanger housing.

The object of the present invention is to provide an improved method of constructing a heat exchanger having a pivotally supported L-shaped bed upon which are stacked a plurality of spaced, parallel brittle plates. The bed includes a norm-ally horizontal first leg upon which the plates are partially supported in an edgewise manner. The bed includes also a second leg rigidly connected with said first leg at an obtuse angle less than approximately 110, said plates being parallel with and partially supported by said second leg. During stacking, the base is pivoted through an angle of approximately to 30 to cause the first and second legs to be raised and lowered, respectively, whereby the respective weights of the plates are utilized to obtain a tight stack. Owing to their orientation on the base, the plates are maintained in tightly stacked relationship as the bed is lowered to its normal position. Consequently, as a result of the invention, the use of auxiliary clamping means for the plates during construction of the heat exchanger is eliminated.

As in the aforementioned Swiss patent, spacer strips are arranged between the plates to define, between alternate pairs of plates, passages that extend normal to passages defined between the remaining plates. As a consequence of the edgewise, inclined orientation of the plates, the compressive load developed in the stack to effect sealing contact between the elements is distributed r uniformly across the brittle plates whereby breakage of the same is avoided.

According to the present invention, uniform transverse support of the lower end plate of the stack is afforded by a mastic mass into which the plate is embedded. At the other end of the stack an expansion unit is provided which compensates for expansion and contraction of the bed and the housing elements. The expansion unit consists of a pair of technical slicate plates between which is arranged a layer of a soft compressible material. It is preferable that the plates of the expansion unit and the embedded plate be somewhat thicker than the other plates for proper absorption of the compressive forces in the stack.

The plates are maintained in position on the bed by a mass of settable material that is pressed into an interspace defined between the expansion unit and a vertical wall of the heat exchanger housing. The filling composition further assures a uniform distribution of load upon the plates.

As a result of the edgewise mounting of the plates in the housing, spray nozzles may be mounted above the stack for directing cleansing and deposit-dissolving fluids downward between the plates. Furthermore, if desired one of the heat exchanging fluids to be directed between alternate pairs of plates may be supplied via the spray nozzles.

Other objects and advantages of the invention will become apparent from a study of the following specification when considered in conjunction with the accompanying drawing, in which:

FIG. 1 is a transverse sectional view of the heat eX- changer taken along line 11 of FIG. 2;

FIG. 2 is a longitudinal sectional view taken along line 2-2 of FIG. 1;

FIGS. 3 and 4 are detailed views of the lower right and left hand ends of the stack of plates of FIG. 2; and

FIG. 5 is a perspective view of the terminal unit that is arranged at the left hand end of the stack of plates of FIG. 2.

Referring to the drawing, the heat exchanger includes a masonry housing containing a chamber defined between end walls 48 and 49, longitudinal walls 50 and 51, and upper and lower horizontal surfaces (not shown). The end walls contain opposed rectangular openings which are closedafter assembly of the heat exchanger elements in the housingby masonry filler 48a and 49a. Adjacent each longitudinal wall is arranged a longitudinal row of stationary pedestals 11 having reduced portions 12 at their upper ends. The pedestals 11a adjacent end wall 49 have reduced ends 12a upon which are fitted inverted U-shaped channels 13a.

Each row of pedestals supports a rigid L-shaped bed 16 having first and second legs arranged at an obtuse angle of less than approximately relative to each other. The horizontal first leg of the bed comprises spaced center and outer beams 20 and 18, respectively, that are connected by transverse inverted U-shaped channels 13 and 15. Channels 13 are supported by pedestal portions 12 and channel 15 is supported by pivot rod 14 welded to channel 13a. The second bed leg comprises triangular plates 22 welded to beams 18 and 20, L-shaped reinforcing beams welded to plates 22, and a transverse metal plate 28 welded to beams 24.

Stacked edgewise upon the first leg of the bed are a plurality of plates 32 and 36 formed of a technical silicate (such as glass or a ceramic) between successive pairs of which are arranged horizontal and vertical spacer strips 34 and 38, respectively. Plate 32 is uniformly supported by a mastic layer 30 (of gypsum paste, for example) positioned on plate 28. The spacer strips are preferably formed of the same material as the plates.

An expansion unit (FIG. 5) is provided at the left-hand end of the stack and comprises a pair of technical silicate plates 40 and 44 between which is arranged a layer 42 of compressible material such as rubber. The interstice between vertical wall portion 48a and the expansion unit is filled with a mastic mass 46, such as gypsum paste.

In order to stabilize the bed in the housing, a concrete slab 54 is supported between the inner beams 18 of the two beds, and concrete slabs 72 are supported by the outer beams 18 and wall supports 70. Concrete slab 58 is supported, adjacent its longitudinal edges, by soft pads 56 on the adjacent upper edges of the two stacks and, at its ends, by soft pads 59 mounted on wall supports 57. Troughs 64 filled with scrap metal are supported by soft pads 68 on the outer edges of the stacks and on the Wall supports 66. Horizontal partition 62 is supported at its ends by wall portions 48a and 49a and defines chambers A and B between slabs 54 and 58. Curved deflecting plates 52 are mounted between the stacks and the longitudinal walls, the concave surfaces of said deflecting plates being directed inwardly toward the stacks as shown.

In the end wall portion 48:: on opposite sides of partition 62 are mounted a .pair of supply and return conduits 60. In operation of the exchanger, a first heat exchanging fluid is supplied to chamber A via the lower conduit 60 and is diverted later-ally outward-as shown by the arrows at-hrough the horizontal passages defined between alternate sets of plates by the strips 34. The fluid is diverted by deflecting plates 58 into chamber B through the upper horizontal passages between the brittle plates as shown by arrows c. The fluid is exhausted via the upper conduit 60. A second heat exchanging fluid in chamber D is directed downw ard-as shown by the arrows dthrou-gh the vertical passages defined between alternate sets of plates by strips 38. This fluid passes through the openings in the bed elements as shown by the arrows e and passes into chamber C. The inlet and outlet openings of chambers D and C, respectively, are not shown in the drawing. The second fluid may be introduced into chamber D via pipes 74 and spray nozzles 76, if desired. In the event that impurities and deposits should be formed on the wall surfaces of the vertical passages, suitable cleaning or deposit-dissolving fluids may be sprayed between the plates by means of the pipes and nozzles.

During construction of the heat exchanger, the masonry housing is formed about the pedestal supported beds, openings being left in the end walls. Each bed is then pivoted in the clockwise direction (FIG. 2) about pivot rod 14 through an angle of approximately 10 to 30. After covering the surface of plate 28 with the layer 30 of a settable material (for example, gypsum paste), plates 32 and 36 and spacer strips 34 and 33 are successively stacked upon plate 28, the lower edges of the brittle plates being partially supported by the first leg of the bed. To facilitate stack-ing, each of the spacer strips may be secured (by gluing, for example) to a surface of one of the two plates between which it is arranged. The expansion element is mounted upon spacer strips arranged on the upper plate 36.

Owing to their orientation, the plates. are stabilized by their respective weights as the bed is lowered to the FIG. 2 position. Adjacent each expansion unit, a portion of the opening in wall 48 is closed by the construction of masonry walls 48a. The mastic 46 (such as sypsum paste) is nowforced into the interstice defined between wall 48a and the adjacent expansion unit, the sides of the interstice being closed by plate means, not shown.

The beds are now secured in place by the mounting of slabs 54 and '72, and slab 58 and troughs 64 are vmounted on the upper edges of the plates. Owing to the weights of slab 58 and troughs 64, the pressure of mastic 46, and the respective weights of the plates themselves, the plates are pressed into tight sealing engagement with the spacer strips. To withstand the compressive forces at the ends of the stack, plates 32, 40 and 44 may be made somewhat thicker than plates 36. Owing to the compressibility of layer 42 and the temporarily non-hardened state of mastic masses 46 and 30, the stress in the stack are distributed uniformly across the brittle heat exchanger elements.

Conduits 60 and partition 62 are now mounted in the end wall openings and are secured in place by the construction of masonry wall 49a and the remaining central portion of wall 48a. Upon hardening of the mastic masses 30 and 46, the construction of the heat exchanger is completed.

Although the housing of the heat exchanger has been described as being formed of masonry and concrete, it is apparent that -for smaller units the housings may be formed of other materials, such as ete-rnite, a synthetic plastic, or a suitable metal.

It will be apparent to those skilled in the art that changes may be made in the method and apparatus described without deviating from the invention set fort in the accompanying claim.

What is claimed is:

The method of constructing a core for a heat exchanger which comprises the steps of providing a rigid L-shaped support having a first leg inclined at an acute angle of approximately 10 to 30 relative to a horizontal plane and a second leg inclined at an obtuse angle less than approximately relative to said first leg; loosely stacking upon said second leg a plurality of heat exchanger plates with spacing members inter-posed therebetween, the edges of said plates engaging said first leg; pivot-ing said support gradually to a position in which said first leg is substantially horizontal; arranging a vertical support adjacent the free end of said stack of plates to define an interstice; and pressing a plastic mass of a settable material into the interstice to hold said plates in the stacked relationship.

References Cited by the Examiner UNITED STATES PATENTS 1,795,909 3/1931 Van Brunt et a1 -166 2,005,515 6/1935 Winker 1651 19 2,251,066 7/1941 Persson et a1 165-167 FOREIGN PATENTS 920,425 1/ 1955 Germany.

JOHN F. CAMPBELL, Primary Examiner.

WHITMORE A. WILTZ, Examiner.

J. D. HOBART, Assistant Exmniner. 

